Detection rules › Sublime MQL
Open redirect: ust.hk
Message contains use of the ust.hk open redirect. This has been exploited in the wild.
Threat classification
Sublime's own taxonomy (not MITRE ATT&CK).
| Category | Values |
|---|---|
| Attack types | Credential Phishing, Malware/Ransomware |
| Tactics and techniques | Open redirect |
Event coverage
| Message attribute |
|---|
| body |
| body.links (collection) |
| headers.auth_summary |
| sender.email |
| type |
Rule body MQL
type.inbound
and any(body.links,
.href_url.domain.domain == "shib.ust.hk"
and strings.icontains(.href_url.path, '/discovery.jsp')
and regex.icontains(.href_url.query_params, '(?:^|&)return=')
)
// negate highly trusted sender domains unless they fail DMARC authentication
and (
(
sender.email.domain.root_domain in $high_trust_sender_root_domains
and not headers.auth_summary.dmarc.pass
)
or sender.email.domain.root_domain not in $high_trust_sender_root_domains
)
Detection logic
Scope: inbound message.
Message contains use of the ust.hk open redirect. This has been exploited in the wild.
- inbound message
any of
body.linkswhere all hold:- .href_url.domain.domain is 'shib.ust.hk'
- .href_url.path contains '/discovery.jsp'
- .href_url.query_params matches '(?:^|&)return='
any of:
all of:
- sender.email.domain.root_domain in $high_trust_sender_root_domains
not:
- headers.auth_summary.dmarc.pass
- sender.email.domain.root_domain not in $high_trust_sender_root_domains
Inspects: body.links, body.links[].href_url.domain.domain, body.links[].href_url.path, body.links[].href_url.query_params, headers.auth_summary.dmarc.pass, sender.email.domain.root_domain, type.inbound. Sensors: regex.icontains, strings.icontains. Reference lists: $high_trust_sender_root_domains.
Indicators matched (3)
| Field | Match | Value |
|---|---|---|
body.links[].href_url.domain.domain | equals | shib.ust.hk |
strings.icontains | substring | /discovery.jsp |
regex.icontains | regex | (?:^|&)return= |